So I have decided to go the same route as the Grinchboy. I have Eibach's and stock shocks, I am replacing them with Koni Yellows, and ZSP springs. I have an automatic 335xi with sunroof, nav and my OEM XI springs were I4, C7. So I THINK I should go with D7, and D4 to get the same results as the Grinchboy, but I am not sure since he has a manual car which weighs less than my automatic.

I tried starting a few threads to get an answer but havent had any replies. I hope someone can post here and let me know if they have done the same thing I am planning to do and what ZSP springs they used.

I did the upgrade before i got my kw set, and I used the d3 rear and d7 front. Just ordered from a guy who was selling his stock springs, so I am not sure what the difference between d3 and the d4 springs are. Springrate is probably a bit tighter on the d4.

most of what i read in these forums say that the spring rates and drop for the zsp sport springs and the eibach kit are almost identical (which is a huge benfit if you are not upgrading shocks too, so you stay close to "oem spec"). I might recommend doing a little research on that topic, as if it were me and I already had the eibach springs, i would not bother getting the zsp. I would even think that if there was a difference, the zsp springs would be a few mm higher than the eibach. I would just get your new koni's and transfer the eibach springs over to them.

most of what i read in these forums say that the spring rates and drop for the zsp sport springs and the eibach kit are almost identical (which is a huge benfit if you are not upgrading shocks too, so you stay close to "oem spec"). I might recommend doing a little research on that topic, as if it were me and I already had the eibach springs, i would not bother getting the zsp. I would even think that if there was a difference, the zsp springs would be a few mm higher than the eibach. I would just get your new koni's and transfer the eibach springs over to them.

This is not true. The drop on the eibach is a lot more. Look up grinchboy's recent posts on it if he does not chime in himself. The RATES on the rears (ZSP + eibach non xi) are all the same, that has nothing to do with the drop. The RATES on nearly all the ZSP springs are the same but they are different lengths, according to how heavy the car is, so that they have nearly the same ride height.

From what we can all tell, the higher the "D" spring number the more weight the OEM ZSP car had, and lower the number less weight. So D3 rear would be for a heavier car than D2, D7 front for heavier than D6 etc.

edit: did you even bother to read this thread? Go back and read previous page.

To ajsalida's point, from my experience I gained about 1" with ZSP as compared to Eibach Prokits. The caveat being, my 335 xDrive (E90 6MT) OEM springs were I3/C6 and I used D6/D5 as replacements. This is different than (what I gleam through research on this forum - not gospel) what a typical 335 RWD e90 with ZSP would be. Based on info on this forum, the typical springs would be D7/D4 or D7/D5 depending on options. One way to get the identical spring for vehicle is to look up on BMWUSA.COM for a used vehicle with the exact year and configuration you want, get the VIN and contact a dealer (such as tischer) and order the ZSP springs against the VIN. You can also get VIN from friends and order the springs accordingly. In my case, I bought used springs from various forum members. My front end springs are from an E92 335i coupe and rear are from an E90 with AT if that helps.

Separate note: I wonder if anyone has tried just swapping the front springs only to a ZSP (D) spring and left the rear as non-ZSP (C) spring. I'm thinking as long as both have similar rating and are either linear or progressive, then it may not matter all that much. This is obviously for those who like the rear height but not the front...

Another minor point, from what I can tell D3/D2 are both rear springs from 335i coupes. And of course as everyone knows, all coupes have ZSP springs, there is no separate ZSP coupe suspension.

edit: GB, I am going to try rear only D2 with Eibach front here in a couple of days. Kind of the reverse of what you're saying. I figure with the D2 being for a bit lighter non-Xi car, and having Eibach in front, maybe I'll get another 0.5". We'll see. Will post pics and results once I get to it.

Another minor point, from what I can tell D3/D2 are both rear springs from 335i coupes. And of course as everyone knows, all coupes have ZSP springs, there is no separate ZSP coupe suspension.

edit: GB, I am going to try rear only D2 with Eibach front here in a couple of days. Kind of the reverse of what you're saying. I figure with the D2 being for a bit lighter non-Xi car, and having Eibach in front, maybe I'll get another 0.5". We'll see. Will post pics and results once I get to it.

Cool! Would love to hear how that handles. It was one of my potential configuration. BTW, let me know if you want to try the D3 rears. I have those still

Here's a couple of pics of mine, doesn't show the wheel gap clearly but I can tell you that it's all gone. The pics show that there still ok clearance in the front even with the splitters at the bottom. I live in the most northern major city in Canada where it snows all day and we live in igloos and I don't see an issue with this ride height.

As for comfort is seems almost the same as stock, I have them paied up with Koni Yellow at full soft as this car is not seeing ANY track duty. Perfect street setup IMO.

Here's a couple of pics of mine, doesn't show the wheel gap clearly but I can tell you that it's all gone. The pics show that there still ok clearance in the front even with the splitters at the bottom. I live in the most northern major city in Canada where it snows all day and we live in igloos and I don't see an issue with this ride height.

As for comfort is seems almost the same as stock, I have them paied up with Koni Yellow at full soft as this car is not seeing ANY track duty. Perfect street setup IMO.

Ok I have Bilstein Sport shocks, Eibach Pro Kit "i" springs, and E86 Z4M rear bump stops waiting in my garage... I will install them when I have some time... I do not need shorter front bump stops because Bilstein Sports shocks have "internal" bumper stops (that's what I've been told in this topic: http://www.e90post.com/forums/showth...0#post14314950) Anyway, looks good on your car, and I hope my car will look good as well

Ok I have Bilstein Sport shocks, Eibach Pro Kit "i" springs, and E86 Z4M rear bump stops waiting in my garage... I will install them when I have some time... I do not need shorter front bump stops because Bilstein Sports shocks have "internal" bumper stops (that's what I've been told in this topic: http://www.e90post.com/forums/showth...0#post14314950) Anyway, looks good on your car, and I hope my car will look good as well

I ordered the Z4 rear bump stops as well but they didn't look much shorter than stock so I just cut stock. Anyways good luck with the install, I did it with a friend and would never do it again lol.

I did the Koni Yellow with 328i Eibach Pro's along with new bump stops (front e36 M3 and rear Z4M) a few months back. The front shocks are set to full soft and rears are 1/2 turn from full soft. I'm experiencing a lot of bottoming out in the front on our roads in spite the fact of avoiding bumps and dips when possible here in New England. Rears have not bottomed out. Is anyone else having the same issue with this setup? Not thinking that cranking up the rebound in the front will help but willing to try if recommended.

I did the Koni Yellow with 328i Eibach Pro's along with new bump stops (front e36 M3 and rear Z4M) a few months back. The front shocks are set to full soft and rears are 1/2 turn from full soft. I'm experiencing a lot of bottoming out in the front on our roads in spite the fact of avoiding bumps and dips when possible here in New England. Rears have not bottomed out. Is anyone else having the same issue with this setup? Not thinking that cranking up the rebound in the front will help but willing to try if recommended.

What kind of tires are you running and what sizes? If they are run flats get rid of them. In the mean time go to 1/2 turn off full soft in front. I have read you are never supposed to run these fully turned either way. IOW always be backed off min 1/4 turn or so. Something about the way the adjuster works.

edit: if the 1/2 turn is better try stepping up in 1/4 turn increments till it feels right. 1 full turn off full soft to me feels very well damped & stiff, on a e92 335xi w/koni+eibach.

What kind of tires are you running and what sizes? If they are run flats get rid of them. In the mean time go to 1/2 turn off full soft in front. I have read you are never supposed to run these fully turned either way. IOW always be backed off min 1/4 turn or so. Something about the way the adjuster works.

edit: if the 1/2 turn is better try stepping up in 1/4 turn increments till it feels right. 1 full turn off full soft to me feels very well damped & stiff, on a e92 335xi w/koni+eibach.

Thanks, I'll give that a try. Also running 18" staggered PS2 RFT's on Arc-8's. Just picked up a BMW spare tire kit on Craigslist today. Once the PS2's wear out, non RFT's will be going on.

I recently installed D7 springs up front and Konis and didnt like the ride height (about an .5-1 inch too high for my taste). I didnt install the D4 rears yet but my assumption is that it will be a nice rear ride height. So I was thinking why not just install the Supreme Power lowering Perches instead of doing the Eibach fronts? I read some old post saying it doesnt work with xi's but their website lets you choose it when you select an xi as your vehicle.

I understand if you want more then .5 inch that it wont satisfy your need, but I think I may be okay with .5.

I've been running D6/D3 ZSP + Bilstein Sports on my 2006 330xi (MT) for about 2 years. Very happy with ride and handling. Ride is improved over stock as you don't get that 'crashing' on larger bumps. If I were to do it over again, I'd probably look for D4 or D5 front ZSP springs as the wheel gap is about .5" more than I'd like in the front. I find the rear gap to be perfect at about 2 of my fingers.

I've considered trying to install spring perches on the front -- but it doesn't bother me enough to risk messing anything up.